| 1. |
- Henningsson, Asa M, et al.
(författare)
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Combinations of indigestible carbohydrates affect short-chain fatty acid formation in the hindgut of rats
- 2002
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Ingår i: Journal of Nutrition. - : Elsevier BV. - 0022-3166. ; 132:10, s. 104-3098
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Tidskriftsartikel (refereegranskat)abstract
- The fermentability and pattern of short-chain fatty acids (SCFA) formed in the hindgut of rats given various combinations of dietary fibers (DF) and resistant starch (RS) were investigated. Highly fermentable indigestible carbohydrates, i.e., guar gum (GG), pectin (Pec) and high amylose cornstarch (HAS), and a DF with a relatively high resistance to fermentation, i.e., wheat bran (WB), were included. The substrates were studied individually or as mixtures (GG + Pec, GG + WB and HAS + WB, 1:1, wt/wt indigestible carbohydrate basis) at a total concentration of 100 g indigestible carbohydrates/kg diet and fed to rats for 13 d. Rats fed Pec had a high proportion of acetic acid in the cecum (76 +/- 2% of total SCFA), whereas those fed GG had the highest proportion of propionic acid (31 +/- 4%, P <0.0005). Rats fed GG and Pec had low proportions of butyric acid (6 +/- 1 and 10 +/- 1%, respectively), whereas those fed both had a higher proportion of butyric acid (15 +/- 3%, P < 0.05). Consequently, the cecal butyric acid pool was twice as high in rats fed the GG + Pec mixture (44 +/- 9 micro mol) as in those fed the individual components (19 +/- 2 and 21 +/- 3 micro mol, respectively, P < 0.05). Rats fed HAS with WB had a greater fecal excretion of SCFA (184 +/- 19 micro mol/d) than those fed the individual components (77 +/- 10 and 116 +/- 12 micro mol/d in rats fed HAS and WB, respectively P < 0.05), suggesting that incorporation of WB delayed the site of fermentation of HAS to the distal part of the hindgut. In conclusion, the combination of indigestible carbohydrates may affect both SCFA patterns and the site of SCFA release in the rat hindgut.
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| 2. |
- Björck, Svante, et al.
(författare)
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Anomalously mild Younger Dryas summer conditions in southern Greenland
- 2002
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Ingår i: Geology. - 0091-7613 .- 1943-2682. ; 30:5, s. 427-430
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Tidskriftsartikel (refereegranskat)abstract
- The first late-glacial lake sediments found in Greenland were analyzed with respect to a variety of environmental variables. The analyzed sequence covers the time span between 14400 and 10500 calendar yr B.P., and the data imply that the conditions in southernmost Greenland during the Younger Dryas stadial, 12800-11550 calendar yr B.P., were characterized by an arid climate with cold winters and mild summers, preceded by humid conditions with cooler summers. Climate models imply that such an anomaly may be explained by local climatic phenomenon caused by high insolation and Fohn effects. It shows that regional and local variations of Younger Dryas summer conditions in the North Atlantic region may have been larger than previously found from proxy data and modeling experiments.
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| 3. |
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| 4. |
- Ek, Sara, et al.
(författare)
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Gene expression profiling of mantle cell lymphonas
- 2003
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Ingår i: Immunology Letters (Abstracts of the 15th European Immunology Congress (EFIS 2003)). - 0165-2478 .- 1879-0542. ; 87:1-3, s. 01-24
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Konferensbidrag (övrigt vetenskapligt/konstnärligt)
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| 5. |
- Mattsson, E., et al.
(författare)
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Staphylococcus aureus induces release of bradykinin in human plasma
- 2001
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Ingår i: Infection and Immunity. - 0019-9567. ; 69:6, s. 3877-3882
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Tidskriftsartikel (refereegranskat)abstract
- Staphylococcus aureus is a prominent human pathogen. Here we report that intact S. aureus bacteria activate the contact system in human plasma in vitro, resulting in a massive release of the potent proinflammatory and vasoactive peptide bradykinin. In contrast, no such effect was recorded with Streptococcus pneumoniae. In the activation of the contact system, blood coagulation factor XII and plasma kallikrein play central roles, and a specific inhibitor of these serine proteinases inhibited the release of bradykinin by S. aureus in human plasma. Furthermore, fragments of the cofactor H-kininogen of the contact system efficiently blocked bradykinin release. The results suggest that activation of the contact system at the surface of S. aureus and the subsequent release of bradykinin could contribute to the hypovolemic hypotension seen in patients with severe S. aureus sepsis. The data also suggest that the contact system could be used as a target in the treatment of S. aureus infections.
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| 6. |
- Viau, Muriel, et al.
(författare)
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Specific in vivo deletion of B-cell subpopulations expressing human immunoglobulins by the B-cell superantigen protein L
- 2004
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Ingår i: Infection and Immunity. - 1098-5522. ; 72:6, s. 3515-3523
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Tidskriftsartikel (refereegranskat)abstract
- Some pathogens have evolved to produce proteins, called B-cell superantigens, that can interact with human immunoglobulin variable regions, independently of the combining site, and activate B lymphocytes that express the target immunoglobulins. However, the in vivo consequences of these interactions on human B-cell numbers and function are largely unknown. Using transgenic mice expressing fully human immunoglobulins, we studied the consequences of in vivo exposure of protein L of Peptostreptococcus magnus with human immunoglobulins. In the mature pool of B cells, protein L exposure resulted in a specific reduction of splenic marginal-zone B cells and peritoneal B-1 cells. Splenic B cells exhibited a skewed light-chain repertoire consistent with the capacity of protein L to bind specific kappa gene products. Remarkably, these two B-cell subsets are implicated in innate B-cell immunity, allowing rapid clearance of pathogens. Thus, the present study reveals a novel mechanism that may be used by some infectious agents to subvert a first line of the host's immune defense.
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